JP2000134970A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the control to change number of rotations of SR motor through the correction setting of the time (application time) to impress the voltage to a power generation coil. SOLUTION: Voltage control of a power generating coil in such case that an SR motor rotates in the constant number of rotations depends on the application timing (t=td) and cutoff timing (t=te) of variable set in response to the actual number of rotations of rotor with reference to the rotating position of rotor. When the number of rotations is changed, the target number of rotations is set. For instance, at the time of acceleration, such target number of rotations is set to higher value. Here, when the actual number of rotations is lower than the target number of rotations, acceleration is determined and the application timing is set to the correct value (t=td') to extend the application time. Meanwhile, at the time of deceleration, the target number of rotations is set to a lower value and deceleration is determined when the actual number of rotations is higher than the target number of rotations, the application timing is set to the correct value (t=td") and the application time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an SR (switched reluctance) motor for driving an oil pump and the like used in a power steering device for an automobile, and more particularly, to a power generation inside an SR motor. The present invention relates to a control for accelerating and decelerating rotation by correcting and setting a waveform of a voltage applied to a coil for use.

[0002]

2. Description of the Related Art Conventionally, PWM (pulse width modulation) control has been adopted as control means for accelerating and decelerating the rotation of a motor. This is a technique of controlling a rotation of a motor by modulating a voltage waveform output to a power generating coil to adjust an amount of supplied energy.

[0003]

In a conventional motor control device employing PWM control, the timing for applying and cutting off the voltage is fixed based on the positional relationship between the stator and the rotor, that is, the rotational position of the rotor. Is set to

However, when the aforementioned timing is variably set in accordance with the rotation speed of the rotor at that time as in the SR motor according to the present invention, it is difficult to employ the aforementioned PWM control.

In view of the above, according to the present invention, a target rotation speed that can be variably set is provided, and a voltage application time is corrected and set based on the target rotation speed to adjust a supplied energy amount. Provided is a motor control device for controlling the rotation of a motor.

[0006]

According to the first aspect of the present invention, there is provided a rotor having four projections including a magnetic material arranged at regular intervals in the circumferential direction, and a rotor arranged at regular intervals in the circumferential direction. And a stator provided with six coils and driven by sequentially applying an excitation voltage of the same phase to one of the coils arranged at an axially symmetric position.
A motor control device is rotated in synchronization with the rotor, and a disk having four slits arranged at predetermined positions corresponding to the respective protrusions, and an excitation voltage of each phase is applied to the position of each slit. It is configured to include a coil and three position signal detection sensors that detect at a predetermined position corresponding to the coil.

Further, as shown in FIG. 1, when each of the sensors detects a position signal, an actual rotation speed measuring means for measuring an actual rotation speed of the motor, and based on the position signal,
Voltage control means is provided to each coil for applying and cutting off an excitation voltage having a corresponding phase according to the measured actual rotation speed.

Further, a target rotation speed setting means for variably setting a target rotation speed, and correcting and setting an application time, which is a time from application of the excitation voltage to interruption of the excitation voltage, according to the set target rotation speed. An application time correction means is provided.

That is, according to the present invention, based on the actual number of rotations of the motor, while performing the optimal voltage control for the operating state at that time,
When changing the number of revolutions, the amount of energy to be supplied is adjusted by variably setting the target number of revolutions, which is the number of revolutions in the target operating state, and correcting the current application time based on the target number of revolutions. It is.

The invention according to claim 2 is characterized in that the application time correction means compares the actual rotation speed with the target rotation speed and corrects the application time. That is, the target rotation speed corrected and set when the rotation speed is changed is compared with the actual rotation speed, and when the actual rotation speed is low, the application time is extended to accelerate (the supplied energy amount is increased). On the other hand, if it is high, the application time is shortened to reduce the speed (the amount of supplied energy is reduced).

The invention according to claim 3 is characterized in that the application time correction means is achieved by correcting a timing (application timing) of applying the excitation voltage.

That is, at the time of acceleration, the application timing is corrected and set to the advance side to extend the application time, while at the time of deceleration, the correction timing is set to the retard side to shorten the application time. The invention according to claim 4 is characterized in that the application time correction means is achieved by correcting a timing (cutoff timing) at which the excitation voltage is cut off.

According to a fifth aspect of the present invention, in the control device for an SR motor used as a motor for generating a steering assist force of a power steering device for an automobile, the target rotational speed setting means needs to increase the steering assist force. Preferably, the target rotation speed is set high in order to accelerate the rotation of the SR motor by extending the application time.

In the invention according to claim 6, the target rotation speed setting means measures at least a steering angle as a parameter for determining the steering assist force, and sets the target rotation speed at a large steering angle requiring an increase in the steering assist force. It is characterized in that the number is set high.

In the invention according to claim 7, the target rotational speed setting means measures at least a vehicle speed as a parameter for determining the steering assist force, and sets the target rotational speed at a low vehicle speed that requires an increase in the steering assist force. Is set high.

[0016]

According to the first aspect of the present invention, the conventional P
In order to adjust the amount of energy supplied by correcting the application time without using the waveform modulation such as the WM control, the rotation speed of the motor is controlled even when the application and cutoff timings are changed according to the actual rotation speed. Can be easily controlled.

Further, since application and cutoff in a high frequency range are not involved, there is also obtained an effect that electrical noise generated when the PWM control is employed can be eliminated. According to the second aspect of the present invention, by performing the correction setting of the application time based on the comparison between the actual rotation speed and the target rotation speed, efficient control according to the current operation state can be performed. .

According to the third and fourth aspects of the present invention, since the application time can be corrected only by the correction setting of the application and cutoff timing, the control is further facilitated. According to the invention of claim 5, when the steering assist force needs to be increased in the power steering apparatus for an automobile, if the target rotation speed is set high, the application time is extended, so that the motor and oil pump If the rotation can be accelerated, and if it is set low, the steering assist force can be reduced, so that an optimal steering assist force can always be generated.

According to the present invention, the required steering assist force is easily determined from the steering angle, and when the steering angle at which the steering assist force needs to be increased is large, the target rotational speed is set high. By doing so, the steering assist force can be easily optimized.

According to the present invention, the required steering assist force is easily determined from the vehicle speed, and when the vehicle speed at which the steering assist force needs to be increased is low,
By setting the target rotational speed high, the steering assist force can be easily optimized.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a system schematic diagram of a control device for a three-phase SR motor according to an embodiment of the present invention. The SR motor is used as a power unit for driving an oil pump of a power steering device for an automobile.

FIG. 3 is a schematic diagram showing the internal structure of the present SR motor. FIG. 4 is a schematic view showing the internal structure of the control device main body of the SR motor, wherein the right side of the figure shows a front view and the left side shows a side view.

The basic configuration of the present SR motor and its control device will be described with reference to FIGS. Reference numeral 1 shown in FIG.
To pressurize a cylinder (not shown) to generate a steering assist force.

The SR motor 1 includes a rotor 11 and a stator 12, as shown in FIG.
The rotor 11 has four protrusions 13 arranged at equal intervals on the outer periphery thereof. On the other hand, the stator 12 has six coils 14u, 14v arranged at equal intervals on the inner circumference thereof.
And 14w.

As shown in the drawing, the coils arranged at the axially symmetric positions are indicated by the same reference numerals. The present SR motor uses U coils for each of the coils 14u to 14w.
The motor rotates by sequentially applying excitation voltages called a phase voltage, a V-phase voltage, and a W-phase voltage.

In the following, each of the coils 14u-14
w corresponds to the phase of the excitation voltage to be applied.
4u, V-phase coil 14v and W-phase coil 14w. The control device for the SR motor configured as described above includes a control device main body 3 and a control unit 4 connected thereto, and the control unit 4 includes:
The steering angle sensor 5 and the vehicle speed sensor 6 are connected.

As shown in FIG.
Has a disk 31 and three position signal detection sensors 3 inside.
2 (only one is shown in the side view for convenience).

The shaft of the disk 31 is connected to the rotor 11 and rotates in synchronization with the shaft. Also,
Four slits 33 are provided, and each slit 33
Is set to have a width such that the central angle is 30 degrees,
As described later, they are arranged at predetermined positions corresponding to the projections 13.

Each of the sensors 32 has a 120 ° angle at three locations corresponding to each of the coils 14u to 14w, as will be described later.
The light-emitting portions 32a are generally disposed,
The light receiving section 32b is included.

The control unit 4 applies the excitation voltage of each phase to the corresponding coil based on the output signals from the sensors 32, the steering angle sensor 5, and the vehicle speed sensor 6, and further cuts off. Execute control.

Next, the basic operation of the present SR motor will be described with reference to FIG. 5A and 5B, for convenience, the rotor 11, the stator 12, the disk 31, and the position signal detection sensor 32, which are the components of the SR motor, are displayed in an overlapping manner.

In FIG. 5, (a) shows the positional relationship between the components at time ta, and (b) shows the same positional relationship at time tb. (C) shows the output signal of each sensor 32 in this time zone and each of the coils 14u-14.
4 shows a basic waveform of an excitation voltage applied to w.

In the present embodiment, each slit 33 is
As shown in (a) and (b), one protrusion
It is shifted by 5 degrees in the advance direction. Further, as shown by the points in the figure, each sensor 32 is connected to each of the coils 14u to 14u.
It is arranged at a position on the straight line connecting w so as to pass over the center of the slit.

In the following, among the sensors 32,
The U-phase sensor 32u is located on the straight line connecting the U-phase coil 14u, the V-phase sensor 32v is located on the straight line connecting the V-phase coil 14v, and the V-phase sensor 32v is located on the straight line connecting the W-phase coil 14w. Is referred to as a W-phase sensor 32w.

Referring to (a), the projection 13 is located at a position facing the U-phase coil 14u, and with reference to (c), the U-phase sensor 32u detects the trailing end of the position signal. At the same time, the V-phase sensor 32v detects the leading edge of the position signal.

In this state, if only the V-phase voltage is applied, an electromagnetic force is generated in the V-phase coil 14v to attract the nearby protrusion 13, so that the rotor 11 rotates in the direction indicated by the arrow in the figure.

Thereafter, until time tb, the V-phase sensor 32
Only v detects the position signal. When the rotor 11 rotates 30 degrees from the state of (a) and reaches the time tb, the state shown in (b) is reached, and the projection 13 faces the V-phase coil 14v. Further, the V-phase sensor 32v detects the fall, and
The phase sensor 32w detects the rise.

In this state, if the V-phase voltage is cut off and the W-phase voltage is applied, the rotor rotates in the same manner as described above.
By turning 30 degrees further from the state of FIG.
Opposite to the phase coil 14w, the W-phase sensor 32w detects a fall and the U-phase sensor 32u detects a rise (tc).

Here, by repeating the same procedure as described above,
The rotor 11 further rotates by 30 degrees and returns to the same state as (a). The time required for the rotor 11 to rotate 90 degrees as described above is considered as one cycle.

During one cycle, each of the sensors 32u-32
It is clear that w detects the position signal one by one in order. Therefore, if these position signals are used as a reference, an excitation voltage can be sequentially applied to the coils 14u to 14w.

By repeating the above control, the rotation of the rotor 11 can be kept constant. Here, as shown in FIG. 6, if the amount of energy supplied is adjusted by extending or shortening the application time Δt in the basic waveform, the above-described rotation can be accelerated or decelerated.

When accelerating, as shown on the left side of FIG.
Correction is set so that the application time Δt is extended like Δt ′. In the present embodiment, the processing for this is (a)
As shown in (5), the application timing (t = ta) is corrected and set earlier by a time corresponding to the difference (Δt′−Δt) of the application time.

Further, according to another embodiment, as shown in (b), the same effect can be obtained even if the cutoff timing (t = tb) is corrected by the same delay. According to still another embodiment, as shown in (c), the difference (Δt′−Δt) of the application time is appropriately distributed to both the correction value of the application timing and the correction value of the cutoff timing, Each timing may be corrected and set at the same time.

On the other hand, when decelerating, the application time Δt is shortened as shown by Δt ″ as shown on the right side of FIG.
This can be achieved by delaying the application timing by a time corresponding to the difference between the application times (Δt−Δt ″).

Further, according to another embodiment, the cutoff timing may be advanced by the same amount as shown in (b), or each timing may be corrected and set simultaneously as shown in (c) as described above.

The control process according to the present embodiment will be described with reference to FIGS. From the above description, each time the rotor 11 rotates by 30 degrees, each of the coils 14u to 14u
Since it is clear that similar voltage control is performed on 14w in order, only V-phase coil 14v will be considered in the following description.

In S1 shown in FIG. 7, an output signal from the V-phase sensor 32v is read. When confirming the position of the slit 33, the V-phase sensor 32v detects a position signal (t =
ta).

In S2, it is determined whether or not the fall of the position signal has been detected. If not detected, the process returns and the output signal of the V-phase sensor 32v is read again.
The same determination is repeated.

On the other hand, if it is detected (t = tb), S3
To start counting the elapsed time after detection by the timer. In S4, the actual rotation speed Nr of the rotor 11 is measured.

The actual number of revolutions can be calculated, for example, from the elapsed time from the previous fall, which is the position signal detection cycle, to the current fall. The cycle is the same as that of rotor 1
1 is equal to the time required to rotate by 90 degrees.

This part corresponds to the actual rotation speed measuring means.
In S5, the application timing (t = td) of the V-phase voltage is set based on the actual rotation speed measured in S4. In the present embodiment, this is determined by the elapsed time (td
-Tb).

In S6, the V-phase voltage cutoff timing (t = te) is set based on the actual rotation speed. Similarly, another elapsed time (te−
tb).

In S7, the processing shown in FIG. 8 is executed. S
At 10, an output signal from the steering angle sensor 5 is read, and a steering angle is input. In S11, the output signal from the vehicle speed sensor 6 is read, and the vehicle speed is input.

In S12, a target rotational speed No, which is a rotational speed for generating an optimal steering assist force, is set from the input steering angle and vehicle speed. This part corresponds to a target rotation speed setting means.

In S13, it is determined whether or not the actual rotational speed Nr is within an allowable range for the target rotational speed No. If it is within the allowable range, it is determined that the actual rotational speed is maintained, and the routine returns to the routine of FIG.

On the other hand, if it is not within the allowable range, the process proceeds to S14, where it is determined whether or not the actual rotational speed Nr is lower than the target rotational speed No. If higher, the process proceeds to S16.

On the other hand, if it is low, the process proceeds to S15, and FIG.
As shown in 0 (a), the application timing (t = td) is corrected and set so that the application time (te-td) is extended (t = td ').

Further, as described above, the cutoff timing (t
= Te), or each timing may be corrected and set at the same time. In S16, the actual rotation speed Nr is
It is determined whether it is higher than the target rotation speed No.

If it is lower, the process returns to the routine of FIG. On the other hand, if it is higher, the process proceeds to S17, and as shown in FIG. 10B, the application timing is corrected and set so as to shorten the application time (t = td ″).

Similarly, the cutoff timing may be corrected or set, or each timing may be corrected and set at the same time. In S8, if the V-phase voltage is not interrupted at time tb, it is forcibly interrupted. While the detection of the position signal depends on the rotation of the disk 31, the cutoff timing is controlled by time, so that a situation in which the application is continued even after the fall is detected (a reverse driving force is generated) is avoided. Therefore, such a process is provided.

At S9, the control shown in FIG. 9 is executed. S
At 20, it is determined whether or not the application timing (t = td, t = td ′, or t = td ″) has been reached.

If not reached, the same determination is repeated until the value is reached, while if reached, the V-phase voltage is applied in S21. In S22, it is determined whether or not the cutoff timing (t = te) has been reached.

If not reached, the same determination is repeated until this is reached, while if reached, the V-phase voltage is cut off in S23. S20 to S23 correspond to the voltage control means.

After returning, the output signal of the V-phase sensor 32v is read again, and the falling of the position signal is monitored. According to the above control, the rotation speed of the motor required to generate the optimum steering assist force is set as the target rotation speed, and the application time is corrected and set by comparing this with the actual rotation speed. The amount of energy to be adjusted can be easily adjusted, and highly efficient control can be performed according to the current operation state.

In the above description, an example is shown in which the present invention is applied as a power means for rotating an oil pump of a power steering device for an automobile. However, various applications as a device for controlling an SR motor used for other purposes. It is clear that there is.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system schematic diagram of an SR motor control device according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing an internal structure of the SR motor according to the first embodiment;

FIG. 4 is a schematic diagram showing an internal structure of a control device main body of the SR motor.

FIG. 5 is a diagram showing a basic operation of the SR motor and a control device therefor;

FIG. 6 is a diagram showing an example of correction of an application time.

FIG. 7 is a flowchart showing a processing routine of a sensor output signal.

FIG. 8 is a flowchart showing processing for correcting and setting an application time.

FIG. 9 is a flowchart showing voltage control.

FIG. 10 is a diagram showing a voltage waveform controlled by the SR motor control device according to the embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 SR motor main body 2 Oil pump 3 Control device main body 4 Control unit 5 Steering angle sensor 6 Vehicle speed sensor 11 Rotor 12 Stator 13 Projection 14 Coil 31 Disk 32 Position signal detection sensor 33 Slit

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) B62D 113: 00 F term (Reference) 3D032 CC21 CC27 DA03 DA23 DA63 EC03 3D033 CA13 CA17 CA20 CA21 EB02 EB04 5H550 AA16 DD09 FF02 FF04 GG01 GG03 HB02 HB16 JJ18 JJ25 LL01 LL35 LL36

Claims (7)

[Claims] A rotor provided with four projections each including a magnetic material arranged at equal intervals in a circumferential direction, and a stator provided with six coils arranged at equal intervals in a circumferential direction; In a control device for a motor driven by sequentially applying an excitation voltage of the same phase to one of the coils arranged at an axially symmetric position, a predetermined position corresponding to each of the protrusions is rotated in synchronization with the rotor. A disk having four slits arranged in the same, and three position signal detection sensors for detecting the position of each slit at a predetermined position corresponding to a coil for applying the excitation voltage of each phase, When the sensor detects a position signal, the actual rotation number measuring means for measuring the actual rotation number of the motor; and, based on the position signal as a reference, corresponding to each of the coils according to the measured actual rotation number. The excitation voltage is applied to,
In addition, a voltage control unit that cuts off, a target rotation speed setting unit that variably sets a target rotation speed, and an application time that is a time from application of the excitation voltage to cutoff is corrected and set according to the set target rotation speed. A motor control device comprising: an application time correction unit; 2. The motor control device according to claim 1, wherein the application time correction means compares the actual rotation speed with the target rotation speed and corrects the application time. 3. The motor control device according to claim 2, wherein said application time correction means is achieved by correcting and setting said application timing. 4. The motor control device according to claim 2, wherein the application time correction means is achieved by correcting and setting the cutoff timing. 5. A control device for a motor used as a motor for generating a steering assist force of a power steering device for an automobile, wherein the target rotation speed setting means sets the target rotation speed when the steering assist force needs to be increased. 5. The motor control device according to claim 3, wherein the rotation speed is set to be high. 6. The motor control device according to claim 5, wherein the target rotation speed setting means measures at least a steering angle as a parameter for determining the steering assist force. 7. The motor control device according to claim 5, wherein the target rotation speed setting means measures at least a vehicle speed as a parameter for determining the steering assist force.